Hello, yes we perform water testing at our stores! Please bring in a sample and we can take a look
Have the water tested. There is a special treatment for the mustard algae. Is your chlorine level showing high after you shocked it? Years ago, i had a similar problem, but I had a chlorune demand problem which wasn't allowing the water to keep a proper level. I had to put 52 bags if shock into the pool (21 foot round). Good luck.
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